Yarn feed device having a feeler stop

ABSTRACT

The yarn feeder of the invention has one or two yarn feeler levers, which monitor the yarn. In order to be able to prevent the monitoring if needed, a feeler barrier is provided. Its actuating device which in the illustrated embodiment is in the form of a handle, is disposed on an outer end of the basic body of the yarn feeder so that it is readily accessible to operators. The position set can also easily be seen from the position of the handle.

FIELD OF THE INVENTION

The invention relates to a yarn feeder, and more particularly, to a yarnfeeder for textile machines.

BACKGROUND OF THE INVENTION

Yarn feeders are used to deliver textile yarn to a textile machine, suchas a knitting machine or other yarn-using machine. The yarn feeder drawsthe yarn from a bobbin held on a creel and delivers it to the textilemachine at a defined tension and/or in a defined quantity, or furnishesthe yarn under defined conditions. Textile machines to which a pluralityof yarns are to be supplied simultaneously usually have a plurality ofyarn feeders. In medium-sized circular knitting machines, for instance,about 100 yarn feeders per knitting machine are provided. To that end,the machine has an annular retainer on which the yarn feeders can besecured. The yarn feeders then protrude in rays outwardly from theretainer and are disposed closely together.

Yarn feeders of this design often require a yarn feeler lever so thatproper and correct yarn feeding can be monitored.

From German Patent DE 3516891 C1, for instance, a yarn feeder fortextile machines is known that has a yarn guide drum driven to rotateabout a vertical axis. The arriving yarn is guided onto the yarn guidedrum, wraps around it several times, and then leads away from it. Bothupstream and downstream of the yarn guide drum, a pivotably supportedyarn feeler lever rests on the yarn and is held by the yarn in a pivotedposition. If the yarn breaks, or if the yarn tension drops markedly, thelever drops downwardly, which is interpreted as an indication of anundesired state.

For drawing in yarns or on startup or in a sampling mode or slow-motionoperation, it may be necessary to stop operation of the yarn feelerlevers.

A similar yarn feeder is known from U.S. Pat. No. 5,860,298. It has abasic body which is provided on one end with a fastening device forsecuring to a retainer of a textile machine. A vertically disposed shaftis rotatably supported on the basic body and carries a yarn guide drumon its lower end. On its upper end, the shaft is connected to pulleysacting as a drive device. The yarn is guided via the yarn guide drum byyarn guide elements, which define a yarn travel path. The yarn travelpath begins at the end of the basic body remote from the fasteningdevice and leads via the yarn guide drum to an end on the outlet side;this end being located near the fastening device. Yarn guide levers formonitoring the yarn are pivotably disposed upstream and downstream ofthe yarn guide drum and rest on the yarn.

When a yarn is drawn in, care must be taken that it be threaded incorrectly beneath the yarn feeler levers.

OBJECTS AND SUMMARY OF THE INVENTION

It is an object of the present invention to provide a yarn feeder whoseconstruction and operation is more simplified and reliable.

A yarn feeder according to the invention has at least one but preferablya plurality of yarn feeler levers. To that end, a feeler barrier isprovided for shifting the yarn feeler lever into a passive state asneeded. This can be obtained either alternatively or cumulatively by twoprocedures. One is shifting the yarn feeler lever to a passive positionwhen the feeler barrier is actuated, and another is shutting off theyarn feeler lever, or in other words interrupting a signal pathconnected to the yarn feeler lever, upon actuation of the feelerbarrier. If the yarn feeler lever is raised upon actuation of the feelerbarrier, for instance, then the yarn can be threaded in more easily, andin the ensuing startup or sampling mode (including a slow-motion mode),any sagging of the yarn will not cause the applicable signal to begenerated. The yarn feeler lever is passive. This makes operationmarkedly easier.

The feeler barrier is manually actuatable and is formed by a slide or bya rotatable or pivotable element. A handle is used for actuation, whichis disposed on an outer end of the basic body that is easily accessibleto an operator in the installed state. If the yarn feeders are to bedisposed, for example, on a fastening ring of a circular knittingmachine, from which they protrude radially outward, then the dispositionof the handle on the end of the basic body remote from the fasteningdevice permits manual access without hindrance, and the position of thefeeler barrier can be seen from outside. In this way, an operator caneasily gain an overview of the status of the yarn feeder. Furthermore,operation in which all the feeler barriers, for instance, of all theyarn feeders (as a rule about 100 of them) have to be actuated, is madeconsiderably easier.

The yarn feeder has a yarn travel path that extends from a yarn inlet toa yarn outlet. The handle of the feeler barrier is preferably disposedin the vicinity of the yarn inlet. Generally, this also is where otherdevices are disposed, such as a yarn brake, knot catcher or the likethat require occasional visual inspection or manual access. Theoperating stations of the yarn feeder are thus concentrated in oneregion.

The handle may be disposed on the flank of the yarn feeder andspecifically on the end of it remote from the fastening device. To thatend, a handle recess or some other indentation may be formed in thebasic body, which is preferably is formed as a housing. The handle maybe visible and accessible in this recess. In addition, it may beconnected to or provided with a signaling device, which makes it easierto detect the position of the feeler barrier. By way of example, thesignaling device may be a colored slide or the like.

The feeler barrier preferably has, or is formed by, a barrier element,and the barrier element preferably is displaceably supported. The handlecan be rigidly joined to the barrier element. This makes for anespecially simple, sturdy construction. The barrier element can then beaccommodated virtually completely in an interior of the basic body.Still other elements, such as switches, detent means for resilientlydefining the position of the barrier element, and the like, can also beaccommodated here.

The yarn feeder may have a plurality of yarn feeler levers, whichpreferably are influenced successively by the feeler barrier. The feelerbarrier then successively pivots the yarn feeler levers into the passiveposition and thus shuts them off in succession. Thus individual yarnfeeler levers, such as the yarn feeler lever on the outlet side, can beswitched to be passive, in order upon machine startup to activate theyarn feeler on the inlet side for monitoring for yarn breakage, yetallowing brief excessive feed quantities on the outlet side.

Other objects and advantages of the invention will become apparent uponreading the following detailed description and upon reference to thedrawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic fragmentary top plan view of a group of yarnfeeders disposed on a ring-like retainer;

FIG. 2 is a perspective of one of the illustrated yarn feeders, asdepicted in FIG. 1, and embodying the present invention;

FIG. 3 is a perspective of a housing part of the yarn feeder shown inFIG. 2;

FIG. 4 is a depiction of two yarn feeler levers and one feeler barrierof the yarn feeder shown in FIG. 2; and

FIG. 5 is a partially schematic plan view of the feeler barrier withassociated elements for the yarn feeder shown in FIG. 2.

While the invention is susceptible of various modifications andalternative constructions, a certain illustrative embodiment thereof hasbeen shown in the drawings and will be described below in detail. Itshould be understood, however, that there is no intention to limit theinvention to the specific form disclosed, but on the contrary, theintention is to cover all modifications, alternative constructions, andequivalents falling within the spirit and scope of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The yarn feeder 1 has an elongated basic body 3, which is formed by atwo-shell housing with an upper part 4 and a lower part 5. On the end ofthe body 3 that in the installed position on the retaining ring twopoints radially inwardly, the basic body 3 is provided with a fasteningdevice 6, which is formed by a jaw 7, opening downwardly, on which aclamping screw is provided. In the region of the jaw 7, the housingparts (upper part 4 and lower part 5) fit over one another to providemutual bracing.

A shaft is rotatably supported on the basic body 3, and its lower endcarries a yarn guide drum 8. Disposed on its upper end are two pulleys9, 10, which are supported rotatably on the shaft. For coupling, asrequired, either the pulley 9 or the pulley 10 to the shaft, a couplingdisk 11 is used, which is supported in axially displacement on theshaft.

The yarn guide drum 8 is disposed in a yarn travel path that is definedby yarn guide elements. These include a yarn inlet eyelet 14, which isopen on one end, a yarn guide eyelet 15 structurally connected to thehousing and located upstream of the yarn guide drum 8, and a yarn guideeyelet 16 and an open yarn outlet eyelet 17 adjoining the yarn guidedrum 8. As needed, the yarn guide eyelet 16 can be closed by a resilienttongue 18 to make it easier to put a yarn in place.

A yarn brake 21, which has two break disks 22, 23 urged magnetically orin other ways toward one another preferably is disposed between the yarninlet eyelet 14 and the yarn guide eyelet 15. The brake disks areretained for lateral and rotatable movement in a bearing device 24. Theyclamp a continuous yarn 25 resiliently between them.

Two yarn feeler levers 27, 28 are pivotably supported on the basic body3 of the yarn feeder 1. The yarn feeler lever 27 is disposed on theinlet side and is constructed in the form of a hoop. It has a yarnfeeler part 31, joining the two legs of the hoop to one another, thatrests on the yarn 25 and that in a raised position held up by the yarnis located between the yarn brake 21 and the yarn guide eyelet 15. If itis not held up by the yarn 25, then it can pivot downward by its ownweight or by spring loading or spring reinforcement.

The yarn feeler lever 28 also is in the form of a hoop and on its lowerend, joining the two legs of the hoop to one another, it has a yarnfeeler part 32. This part rests on the yarn 25 and is kept in the raisedposition by the yarn. If the yarn tension decreases, or if the yarn 25forms a sagging loop, then the yarn feeler lever 28 sags downward underthe influence of its own weight and/or with spring reinforcement.

To enable shifting the yarn feeler levers 27, 28 into a raised passiveposition as needed, a feeler barrier, which can be seen particularlyfrom FIGS. 4 and 5, is disposed on the yarn feeder 1. As seen first fromFIG. 3, a hoop 36 connected electrically to ground is disposed in thelower housing part 5. The hoop 36 in this instance is formed by asuitable sheet-metal strip bent nearly into a U-shape. Its two legs 37,38 extend inward approximately parallel to one another along bothhousing walls that face one another in the form of flanks. In theimmediate vicinity of trapezoidal cutouts 41, 42, 43, 44 provided in theside walls of the housing part 5, the legs 37, 38 of the hoop 36 areprovided with L-shaped notches 45, 46, 47, 48, which form bearing pointsfor inwardly-bent ends of the hoop-like yarn feeler levers 27, 28. Forsecuring these ends of the yarn feeler levers 27, 28 in the bearingpoints or positions, the upper housing part 4, as shown in FIG. 2, isprovided with protrusions 51, 52, which fit into the trapezoidal cutouts41, 42, 43, 44 and on their face end have a half-round recess fordefining the pivot axes 53, 54 (FIG. 4) of the yarn feeler levers 27,28.

Between the inwardly bent ends of the yarn feeler levers 27, 28,roller-like plastic parts 55, 56 are provided, which join together theends of the legs of each yarn feeler lever 27, 28 that point to oneanother. The plastic parts 55, 56 are disposed approximatelyconcentrically to the respective pivot axis 53, 54 and act as switchactuating elements. They each have a slit-like recess 57, 58 oftriangular cross section extending approximately parallel to therespective pivot axis 53, 54, in which recess an outwardly-bent free endof one leg of a respective U-shaped spiral spring 59, 60 is seated. Theother leg of each spiral spring 59, 60 has an outwardly-bent endsupported on an abutment, which is formed by a contact cleat 61, 62. Thespiral springs 59, 60 serve to relieve the weight of the yarn feelerlevers 27, 28 and in addition serve as switch elements. To that end,resilient contact tongues 63, 64 are provided, which protrude into thepivoting range of the end of the U-shaped springs 59, 60 at which thelegs are joined.

The barrier element 71 is formed by a substantially flat sheet-metalstrip or slide, on which a tab or handle 75 is bent at one end at aright angle (FIG. 5). As shown in FIG. 2, this tab is disposed in ahandle recess 77 formed laterally on the end of the basic body 3 remotefrom the fastening device 6. The tab serves to push the barrier element71 back and forth longitudinally, as indicated by arrow 78 and FIGS. 4and 5, in order to block and release the yarn feeler levers 27, 28.

The barrier element 71 has a first control face 81, associated with theyarn feeler lever 27, and a second control face 82, associated with theyarn feeler lever 28. The control faces 81, 82 are oriented at an acuteangle to the direction of displacement of the barrier element 71 and arealigned such that they press the lugs or protrusions 73, 74 of the yarnfeeler levers 27, 28 downwardly whenever they come into engagement withthem. The spacing between the control faces 81, 82 deviates from thespacing between the lugs 73, 74 so that, for examples (if the spacing atthe barrier element 71 is less) the control face 82 first comes intocontact with the lug 74 and then the control face 81 comes into contactwith the lug 73. The control faces 81, 82 preferably are initiallyramp-like and then change into a retaining portion oriented parallel tothe displacement direction 78. The control faces 81, 82 are preferablyformed by portions bent laterally away from the barrier element 71.

The barrier element 71 preferably can be locked in a plurality ofdisplacement positions. This purpose is accomplished by a detent device83, which is formed by a lug 84 protruding laterally away from thebarrier element 71 and by one or more recesses 85, 86, 87 in the housingwall toward the barrier element 71. The lug 84 is preferably is formedon the laterally resilient end, remote from the handle 75 of the barrierelement 71. The notches or recesses 85, 86, 87 in the housing wall aredisposed such that when the lug 84 is seated in the first recess 85,neither control face 81, 82 is in contact with either of the lugs 73,74. If the lug 84 engages the second recess 86, then the control face 82has already pressed the lug 84 downward and thus the yarn feeler lever28 upward. If the lug 84 has snapped into the third recess 87, then inthe meantime the second control face 81 also has advanced the yarnfeeler lever 27 upwardly.

Alternatively, instead of the slide acting as a barrier element 71, apivotable element can be used, such as a lever, or a shaft or tube thatis rotatable about its longitudinal axis. These elements may likewise beprovided with barrier slots or barrier elements.

The yarn feeder 1 described above functions as follows:

Once all the yarn feeders 1 are secured to the retaining ring 2, then ayarn is first brought to each yarn feeder 1. To enable easy introductionof the yarn into the respective yarn feeder 1, the feeler barriers 70are first actuated, in that the handles 75 of all the yarn feeders 1 areactuated or in other words are pulled radially outward with respect tothe fastening ring 2. The yarn feeler levers 27, 28 pivot upwardly inthe process. The yarn feeler part 31 of the yarn feeler lever 27 pivotsupwardly between the brake 21 and the yarn inlet eyelet 15. The yarnfeeler part 32 pivots upwardly between the yarn guide eyelet 16 and theyarn outlet eyelet 17. Once all the yarns have been put in place, theknitting machine can be started up cautiously, in slow motion. Ifneeded, to that end the inlet-side yarn feeler levers 27 can beconverted from their passive to the active state or in other wordsreleased. To that end, the various handles 75 of the barrier elements 71are thrust radially inwardly somewhat (by one stage) so that therespective lug 84 moves out of the recess 87 (FIG. 5) and snaps into therecess 86. This can be accomplished with all the yarn feeders 1. Themachine can then be operated in this condition until all the yarns aretraveling properly. Once that state is attained, then by further pushingthe handles 75 of the yarn feeders 1 radially inwardly, the respectiveoutlet-side yarn feeler levers 28 can also be released. Now, both yarnfeeler levers 27, 28 of each yarn feeder 1 are active.

What is claimed is:
 1. A yarn feeder (1) particularly adapted formounting and use in a textile machine, comprising: an elongated body (3)having a fastening device (6) at one end for securing the yarn feeder(1) to a retaining device (2) of a textile machine, yarn guides (14, 15,16, 17) supported on the body (3) for defining a yarn travel path, ayarn guide drum (8) disposed in the yarn travel path, said drum beingrotatably mounted on the body (3) and having a drive device (9), atleast one yarn feeler lever (27) disposed in the yarn travel path, saidyarn feeler lever (27) being pivotably supported on the body (3) and inan active state rests on a yarn (25) being fed by the yarn feeder, afeeler barrier (70) for selectively shifting the yarn feeler lever (27)to a passive inoperable state, and said feeler barrier (70) having anoperating handle (75) disposed on the feeler barrier and beingaccessible from an end of the elongated body (3) remote from thefastening device (6).
 2. The yarn feeder of claim 1 in which said feelerbarrier (70) and handle (75) are rigidly joined to one another.
 3. Theyarn feeder of claim 1 in which said feeler barrier (70) includes abarrier element (71) supported for movement back and forth between alocking position in which the yarn feeler lever (27) is maintained in aposition of repose in said passive state, and a release position whichleaves the yarn feeler lever (27) unaffected by the barrier element (71)and free to assume an active state on a yarn being fed by the yarnfeeder.
 4. The yarn feeder of claim 3 which said barrier element (71)has a barrier face (81) that is engageable with the yarn feeler lever(27) upon displacement of the barrier element to a barrier position forshifting the yarn feeler lever (27) to said position of repose.
 5. Theyarn feeder of claim 1 in which said feeler barrier (70) has a pluralityof detents (83) for locking the feeler barrier (70) in any one of aplurality of selected positions.
 6. The yarn feeder of claim 5 in whichsaid retaining device surrounding a textile machine with which the yarnfeeder is used, is mountable on a circular mounting member, and saiddetents can be observed by an operator at one end of the yarn feederlooking radially toward the textile machine.
 7. The yarn feeder of claim5 in which said feeler barrier (70) includes an elongated barrierelement (71), and said handle is formed by a tab protruding laterally ofthe barrier element and transversely to the direction of movement of thefeeler barrier element (70).
 8. The yarn feeder of claim 5 in which saidhandle (75) is disposed in an indentation (77) formed in the body. 9.The yarn feeder of claim 1 including a yarn brake (21) disposed in theyarn travel path, and said handle (75) being disposed beside the yarnbrake (21).
 10. The yarn feeder of claim 1 in which said feeler barrier(70) includes an electric switch (60, 64, 59, 63) actuatable in responseto movement of the feeler lever (27).
 11. The yarn feeder of claim 1including a switch for detecting the position of the barrier element(71).
 12. The yarn feeder of claim 1 including a plurality of yarnfeeler levers (27, 28), and said feeler barrier (70) is operative forcontrolling the passive state of each of the feeler levers (27, 28). 13.The yarn feeder of claim 12 in which said feeler barrier (70) isoperable for successively controlling the passive state of saidplurality of yarn feeler levers (27, 28).